DS.JSONSerializer#extractErrors()

extractErrors is used to extract model errors when a call to DS.Model#save fails with an InvalidError. By default Ember Data expects error information to be located on the errors property of the payload object.

This serializer expects this errors object to be an Array similar to the following, compliant with the JSON-API specification:

{
  "errors": [
    {
      "detail": "This username is already taken!",
      "source": {
        "pointer": "data/attributes/username"
      }
    }, {
      "detail": "Doesn't look like a valid email.",
      "source": {
        "pointer": "data/attributes/email"
      }
    }
  ]
}

The key detail provides a textual description of the problem. Alternatively, the key title can be used for the same purpose.

The nested keys source.pointer detail which specific element of the request data was invalid.

Note that JSON-API also allows for object-level errors to be placed in an object with pointer data, signifying that the problem cannot be traced to a specific attribute:

{
  "errors": [
    {
      "detail": "Some generic non property error message",
      "source": {
        "pointer": "data"
      }
    }
  ]
}

When turn into a DS.Errors object, you can read these errors through the property base:

{{#each model.errors.base as |error|}}
  <div class="error">
    {{error.message}}
  </div>
{{/each}}

Example of alternative implementation, overriding the default behavior to deal with a different format of errors:

import DS from 'ember-data';

export default DS.JSONSerializer.extend({
  extractErrors: function(store, typeClass, payload, id) {
    if (payload && typeof payload === 'object' && payload._problems) {
      payload = payload._problems;
      this.normalizeErrors(typeClass, payload);
    }
    return payload;
  }
});